The TTSIOD CPU-based phong renderer with soft-shadow mapping is
a bit of a roller coaster between Ubuntu releases. The good news, however, is
that with Ubuntu 10.10 the performance is better than Ubuntu 8.04.4 and at a high
point since Ubuntu 9.10, but it's not quite at the speed as we found with Ubuntu
9.04.

The Bullet Physics Engine performance does not change much by
the rest of the Ubuntu software stack.

Due to a regression in the GNU Compiler Collection or elsewhere
in the Ubuntu Linux OS, the past three releases have taken noticeably longer to
complete their ray-tracing task than in older versions.